Integrated racking and contact controlling mechanism for circuit breakers



Jan. 30, 1962 c. oonwm, JR 3,019,309

INTEGRATED RACKING AND CONTACT CONTROLLING MECHANISM FOR CIRCUIT BREAKERS Filed Feb. 1, 1960 3 Sheets-Sheet 1 Jan. 30, 1962 E c GOODWIN JR 3,019,309

INTEGRATED RACKING AND CONTACT CONTROLLING MECHANISM FOR CIRCUIT BREAKERS Filed Feb. 1, 1960 5 Sheets-Sheet 2 JMMJto/L 50140644 ,8- gnaw/ 44,31

Jan. 30, 1962 E c, GOODWIN, JR 3,019,309

INTEGRATED RACKING AND CONTACT CONTROLLING MECHANISM FOR CIRCUIT BREAKERS Filed Feb. 1, 1960 3 Sheets-Sheet 3 United States Patent INTEGRATED RACKING AND CONTACT CONTROLLING MECHANISM FOR CIR- CUIT BREAKERS Edwin C. Goodwin, Jr., Canton, Mass., assiguor to Allis- Chalmers Manufacturing Company, Milwaukee, Wis. Filed Feb. 1, 1960, Ser. No. 5,951 9 Claims. (Cl. 20050) This invention relates to circuit breaker structures for mounting in a cubicle and more particularly to a new and improved integrated transmission mechanism for selectively actuating a circuit breaker racking mechanism and an arcing contact controlling mechanism. This integrated action mechanism is particularly concerned with but not limited to manually operated low voltage air circuit breakers of the type used in metal enclosed drawout switchgear.

A low voltage air circuit breaker is composed essentially of a fixed contact structure and a movable contact structure operated by a mechanism which may be either motor, solenoid or manually actuated. These compenents are mounted on a supporting frame. In order to facilitate the installation of this breaker it may be equipped with suitable wheels and a racking device both attached to the supporting frame. When a breaker of this type is installed in metal enclosed drawout switchgear, it is first placed in the free position with the wheels on the extended drawout supporting structure and then racked through the disconnect and test positions to the connection position, in which position its arcing contacts may be closed.

In accordance with the invention claimed a new and improved mechanism for mounting a circuit breaker structure in a cubicle and controlling its arcing contacts is provided. This mechanism integrates the action for both racking and circuit breaker contact controlling movement in single sequential operations. A driving shaft is utilized for actuating the racking means and the arcing contacts upon rotation thereof. This driving shaft is sequentially detachably connected to two driven shafts for rotation thereof. One of the driven shafts actuates the racking means while the other of the driven means charges a contact closing spring load means.

It is, therefore, one object of this invention to provide a new and improved transmission mechanism.

Another object of this invention is to provide a new and improved integrated transmission mechanism for selectively actuating a circuit breaker racking mechanism and an arcing contact controlling mechanism.

A further object of this invention is to provide a new and improved manually operable lever mechanism which sequentially racks a circuit breaker in a cubicle and charges the closing springs of a pair of arcing contacts.

Objects and advantages other than those set forth will be apparent from the following description when read in connection with the accompanying drawings, in which:

FIG 1 is a vertical cross sectional view partly in elevation of a circuit breaker structure taken along line I--I of FIG. 2 utilizing a transmission mechanism and employing the present invention; 7 g

FIG. 2 is a partial front elevational view of the circuit breaker structure shown in FIG. 1 in the neutral position of the racking and arcing contact controlling mechanism; I

Patented Jan. 30, 1962 FIG. 3 is a partial top view of FIG. 2 showing the circuit breaker racking and arcing contact controlling mechanism;

FIG. 4 is an enlarged partial view of the circuit breaker racking and arcing contact controlling mechanism shown in FIG. 2 in the arcing contact controlling posi tion;

FIG. 5 is an enlarged partial view similar to FIG. 4 showing the circuit breaker and arcing contact controlling mechanism in the racking position;

FIG. 6 is an enlarged detailed view of the spring mechanism for the selector lever shown in FIGS. 4 and 5 taken along line VIVI of FIG. 1; and

FIG. 7 is an enlarged view of the cover enclosing the racking and arcing contact controlling mechanism showing the possible positions of the selector lever.

Referring more particularly to the drawing by characters of reference FIGS. 1-7 illustrate a circuit breaker 10 utilizing an integrated transmission mechanism 11 for selectively actuating a circuit breaker racking mechanism 12 and an arcing contact controlling mechanism 13. The transmission mechanism 11 comprisesa pinion or driving shaft 14 having fixedly mounted thereon a first gear or sprocket 15 and a second gear or pinion 16. Shaft 14 is rotated by means of a suitable electric motor 17 or by means of a manually rotatable handle 18. R0- tation of handle 18 delivers'energy through shaft 19, worm 20 and worm gear 21 into shaft 22 to chain sprocket 23. A flexible drive chain 24 connecting sprockets 23 and 15 causes rotation of driving shaft 14 in the same manner as does motor 17.

' This manually integrated actuating mechanism comprising shaft 19 and Worm 20 is supported in such a manner that worm 20 is maintained in continuous engagement with worm gear 21 which is supported by but not permanently attached to shaft 22. To shaft 22 are fastened pins 25, 26, 27, 28 and 29. Pin 28 engages'a slot 30 in hub 31 of worm gear 21 at all times while pins 25 and 29 may be caused to engage a slot 32 in hub 33 of sprocket 23 and a slot 34 in a hub 35 of rotatably mounted racking crank 36 by displacing shaft 22 to the left and right respectively as shown in FIGS. 4 and 5.

Displacement of shaft 22 is effected by movement of a selector lever 40 acting through a pin 41 and a block 42. Block 42 is supported by but not attached to shaft 22 and pin 41 extends from block 42 into a loose fitting aperture in lever 40. Block 42 is contained between pins 26 and 27 on shaft 22. In the position shown in FIG. 2 handle 18 is inoperative as far as conveying motion to driving shaft 14 since shaft 22 is disengaged from sprocket 23. In the manual driving position lever 40 is moved from the position shown in FIG. 2 to the left as shown in FIG. 4 so that shaft 22 and sprocket 23 are interconnected. During the time that handle 18 is rotated to drive shaft 14 the shaft of the electric motor 17 is also rotated because they are directly connected together. Further, during the time that motor 17 is driving shaft 14 sprocket 23 and chain 24 are also driven although at this time lever 40 has disconnected shaft 19 from shaft 14. i

Rotation of driving shaft 14 and gear 16 by chain 24 causes rotation of a gear 45 which is in meshing engagecorresponding pin 48 on an eccentric 49. Eccentric 49 is supported by shaft '46 for rotation thereon. lockwise rotation of gear 45 engages pin 47 on gear 45 with pin 48 on eccentric 49 and revolves eccentric 49 clockwise as shown in FIG. 1 about its fixed center, which is the center of shaft 46, driving a connecting rod 58 to the right. Connecting rod 58 is fixedly mounted on a housing 51 supported by eccentric 49 and rotatably movable therewith during at least a part of the cycle of rotation of eccentric 49, as is well known the art.

The motion of connecting rod 50 to the right compresses a pair of load springs (stored energy devices) 52 and 53 as shown in FIGS. 1 and 2 that function as a unit throughlink mechanism 54-and bar 55. At the instant that springs 52 and 53 are fully charged, latch'roll 56 aflixed to housing-51 engages a prop latch 57, thus holding the fully charged springs latched and ready to be discha'rged to-perform a useful function, forexample, closingthe'movable cooperating arcing contacts 76 and 71 of a circuit breaker. The prop latch 57 may be released by a-solenoid mechanism 60 which upon movement of "itsarmature rod 61 tothe right as shownin FIG. 1 actuates prop latch-57 through a lever 62 and shaft 62" to rotate itclockwise releasing latch roll 56, thereby permittinghousing 51 and connecting rod 50 to rotate under the forceof springs52 and 53. Once the stored energy or-loadsprings 52 and 53 have been released the springs can again-be recharged automatically by motor 17 or manually by handle 18 as explained above.

Toprevent overloading of the spring charging system whenlateh roll 56-engages proplatch 57, gear'45 which is driven by the driving shaft 14 is shaped to disengage from --bear l6-onshaft l4 at the fully chargedposition of the stored energy springs 52 and 53. This disengagement is accomplished by the removalof a-segment of the teeth from the periphery of the gear. Flexible teeth 63 (shown in FIG. 1) are provided at the end of theopen segment ;to facilitate reengagement of the gears 16 and 45 at the -3.:p01'ti0110f a second partof .theperiphery of gear 45 -by ---means of bolts 67 which may -threadly engage with suitable openingsalong theperiphery ofthe gear structu're. metallicst'rip=material of-resilient properties which are Teeth 63 -are shown as formed of overlapp g so -arranged*as to'havespaced tooth gear edges. The

span -of flexible teeth=arearranged in the open segment 'ofthe tooth peripheryof gear 45 adjacent one end of the normal rgear teeth' 68 ofgear'45. Gear teeth 68 arra'nged along a firstfpart of theperiphery of gear 45 have solid tooth segments while-teeth 63 arefiexible so asto=yield if 'necessarynpon engagement with the teeth on piniomor-gear -16 or upon initial movement of shaft -'14-'to automaticallyposition gears 16 and 45 in proper ineshing engagement at the start of each driving cycle of -shaft 14. This arrangement of flexible teeth at the beginning part of aspa'n of teeth provides unimpeded reengagementof the charging motor pinion gear 16 with the "charging mechanism for springs 52 and 53 immediately after-each energy releasing action of the prop latch mechanism'57.

-As -shownin FIG.'-1 the arcing contact mechanism in- -cluding-the-pair of cooperatingcontacts'70 and 71 are in the contact closed position with the stored energy springs 52'and-53" charged. Springs 52 and 53 are connected to=the arcing contacts by means of a bell crank 72 pivotally mounted at 73to the frame of the circuit breaker.

One end; of hell crank 72-is pivotally connected by pin 74 to-link mechanism 54-and bya-pin 75 to link 76. Link 76 is pivotally connected at 69 to a rotatable closing cam 77 which acts against toggle roll78 moving a'toggle linkage comprising toggle arms 79 and 80 to the right as shown in FIG. 1 about a releasable center point 81 to close the arcing contacts. When the arcing contacts are in their closed position the toggle is arranged in an overcenter position in the usual manner. The closing cam 77 will remain in its upper position reached when forcing the toggle linkage to its overcenter position until the closing springs 52 and 53 are recharged. Recharging of the closing springs 52 and 53 will rotate bell crank 72 in the counterclockwise direction to the position shown in FIG. 1 thereby drawing the closing cam 77 down to the position shown for another arcing contact closing operation.

When the circuit breaker is mounted in or removed from a cubicle 88 the circuit breaker is racked in and out by the racking mechanism 12. Racking mechanism 12 comprises a pair of pivotally mounted racking cranks 82 -(one of which is shown in FIG. 1) each provided with a slot 83 at one end thereof for engaging with fixed pins 86 one of which is shown in FIG. 2 attached to the sides of '87. Racking crank-36 is rotatably mounted on shaft 22.

In order to actuate the racking mechanism 12 the selector lever 40 is moved to the racking positionshown in FIG-5. In this position shaft 22 is moved to the right and .pin 29 engages with slot 34 of hub 35 of arm 36. Upon rotation of shaft-22mm 36 is rotated to actuate cranks SZ-torackthebreakerin or-remove itfromthe cubicle.

FIG. 6 illustrates the'spring mechanism 89 of theselector lever 40. In thevertical position shown the selector lever 40 would be in its unbiased position. When the selector lever 40 is moved to its spring charging or racking positions shown in FIG. 71ever-40 is under-bias of spring 89 tending to return the selector lever to its natural or vertical position.

In accordance with the structure described :andshown 1n the drawings when the selector lever is in the-neutral orvertical position the electric motor isenergized if the charging springs-52 and 53 arenot 'biased asshown in FIG. -1 then motor,l7 rotates shaft, 14-and Tpinion16 and gear :45. Rotation .of gear ":45 "engages pin 47 with pin 48. on eccentric 49 which revolves. eccentric :49. clockwise about shaft 46. drivingthe connecting rod 50' to the right. The motion of the 1connectingrod-50 totheright compressesssprings 52 and. 53. ..-At;.the instantsprings 52-and '53 are fully charged, latch roll 56 afiixedto connecting rod housing 51 engages prop. latch 57 thusholding the fully charged springs latched andreadyto be discharged to close'the. breaker byreleaseof prop latchr57 bythe solenoid mechanism 60. Once the storedenergysprings have been released 'and the breaker closed, springs 52 and 53 are again recharged automatically bythe motor delivers energy through.shaft.19, worm 20 andwormgear 21 into shaft 22 and. to. chain sprocket .23. flexible drive chain .'24 connecting sprocket 23 and sprocket or gear-15causes rotationofpinion; 16in the same manner as:motor.17. .The remainder of the sequence for charging and discharging springs 52 and.53 is the samev as .above described under the motor energized sequence. of this structure.

Manual releaseof the ,storedaenergy springs '52:.and 53 to close the arcing contacts 70 and 71 is accomplished by depressing mechanical closing button 90 which rotates prop latch 57 in the same manner as solenoid mechanism 60. Once released and the breaker contacts closed the springs 52 and 53 may be again recharged manually as previously described.

To rack the circuit breaker structure into its energized position in the cubicle the selector lever 40 is placed in the neutral position and the breaker is moved into the cubicle until the slots in the racking cranks 82 engage with fixed pins attached to the sides of the cubicle. To reach the racking position in the cubicle certain stops or interlocks in the cubicle are overcome in a predetermined manner. Once these interlocks are overcome in given positions in the cubicle the breaker contacts can be closed or opened. The breaker racking action occurs by rotating cranks 82 which are fixed to shaft 84 and are rotated by arm 85. Arm 8'5 is actuated by shaft 22 through racking crank 36 and links 87.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

Having now particularly described and ascertained the nature of my said invention and the manner in which it is to be performed, I declare that what I claim is:

1. A circuit breaker structure for mounting in a cubicle comprising a frame, a pair of cooperating movable arcing contacts mounted on said frame, means for causing relative movement between said contacts, a racking means mounted on said frame for cooperating with the cubicle for varying the position of said frame within the cubicle upon actuation thereof, a dual purpose driving means for actuating said racking means and said contact movement means, and means for selectively connecting said driving means to said racking means and said contact movement means.

2. A circuit breaker structure for mounting in a cubicle comprising a frame, a pair of cooperating movable arcing contacts mounted on said frame, means for causing relative movement between said contacts, a racking means mounted on said frame for cooperating with the cubicle for varying the position of said frame within the cubicle upon actuation thereof, a dual purpose'driving means for selectively actuating said racking means and said contact movement means, means for selectively connecting said driving means to said racking means and said contact movement means, and manual means for actuating said driving means.

3. A circuit breaker structure for mounting in a cubicle comprising a frame, a pair of cooperating movable arcing contacts mounted on said frame, spring means for causing relative movement between said contacts, a racking means mounted on said frame for cooperating with the cubicle for varying the position of said frame within the cubicle upon actuation thereof, means for biasing said spring means for causing relative movement between said contacts, a dual purpose driving shaft for selectively actuating said racking means and said spring biasing means upon rotation thereof, and means for selectively connecting said driving means to said racking means and said spring biasing means.

4. A circuit breaker structure for mounting in a cubicle comprising a frame, a pair of cooperating movable arcing contacts mounted on said frame, means for causing relative movement between said contacts, racking means mounted on said frame for cooperating with the cubicle to vary the position of said frame in the cubicle upon actuation thereof, a driving shaft mounted for rotation thereof, a first driven shaft, a second driven shaft, said first driven shaft being detachably connected to said driving shaft for rotation thereby, said second driven shaft being detachably connected to said driving shaft for rotation thereby, means for connecting said first driven shaft to said racking means for actuation thereof, means for connecting said second driven shaft to said contact movement means for causing relative movement of said contacts, and a mechanism for selectively connecting said first and said second driven shafts to said driving shaft.

5. A circuit breaker structure for mounting in a cubicle comprising a frame, a pair of cooperating movable arcing contacts mounted on said frame, means for causing relative movement between said contacts, racking means mounted on said frame for cooperating with the cubicle to vary the position of said frame in the cubicle upon actuation thereof, a manually rotatable driving shaft, a first driven shaft, a second driven shaft, said first driven shaft being detachably connected to said driving shaft for rotation thereby, said second driven shaft being detachably connected to said driving shaft for rotation thereby, means for connecting said first driven shaft to said racking means for actuation thereof, means for connecting said second driven shaft to said contact movement means for causing relative movement of said contacts, and a lever mechanism for selectively connecting said first and said second driven shafts to said driving shaft.

6. A circuit breaker structure for mounting in a cubicle comprising a frame, a pair of cooperating movable arcing contacts mounted on said frame, means for causing relative movement between said contacts, racking means mounted on said frame for cooperating with the cubicle to vary the position of said frame in the cubicle upon actuation thereof, transmission means for actuating said racking means and said contact movement means upon actuation thereof, said transmission means comprising a driving shaft, a first driven shaft, a second driven shaft, said first driven shaft being rotatably connectable to said driving shaft, said second driven shaft being rotatably connectable to said driving shaft, means for connecting said first driven shaft to said racking means for actuation thereof, means for connecting said second driven shaft to said contact movement means for actuation thereof, and a mechanism for selectively connecting said first and said second driven means to said driving means.

7. A circuit breaker structure for mounting in a cubicle comprising a frame, a pair of cooperating movable arcing contacts mounted on said frame, racking means mounted on said frame for cooperating with the cubicle to vary the position of said frame in the cubicle upon actuationthereof, a driving shaft mounted for rotation thereof, a first driven shaft, a second driven shaft, said first driven shaft being detachably connected to said driving shaft for rota tion thereby, said second driven shaft being detachably connected to said driving shaft for rotation thereby, means for connecting said first driven shaft to said racking means for actuation thereof, a load device, means for connecting said second driven shaft to a mechanism for biasing said load device, means for connecting said load device to at least one of said contacts for closing said contacts upon release of saidload device, and a lever mechanism for selectively connecting said first and said second driven shafts to said driving shaft.

8. A circuit breaker structure for mounting in a cubicle comprising a frame, a pair of cooperating movable arcing contacts mounted on said frame, racking means mounted on said frame for cooperating with the cubicle to vary the position of said frame in the cubicle upon actuation thereof, a driving shaft mounted for rotation thereof, a first driven shaft, a second driven shaft, said first driven shaft being detachably connected to said driving shaft for rotation thereby, said second driven shaft being detachably connected to said driving shaft for rotation thereby, means for connecting said first driven shaft to said racking means for actuation thereof, a spring, means for connecting said second driven shaft to a mechanism for biasing said spring, means for connecting said spring to at least one of said contacts for closing said contacts upon release of said biased spring, and a lever mechanism for selectively connecting saidfirst and said second shafts to said driving said racking means and said contact controlling means. shaft.

.9. A circuit breaker structure .mounted on a frame kefel'eflcescited in the file of this Patent :for positioning in .a cubicle, said structure comprising .a UNITED STATES PATENTS pair of cooperating arcing contacts, means for controlling 5 the movement of said contacts, and aracking means, said i g g et a1 g g trackingrneans being mounted on said frame and cooperat- 2792462 1957 ing with thecubicle to varyvsaid structures position within 6 41 L D ay f1958 the cubicle upon actuation thereof, and .a .dual purpose 2921998 1960 wintegrated transmission .means for selectively actuating 10 o Omy e a 

